Efficacy and Safety Study of Guselkumab in the Treatment of Participants With Active Psoriatic Arthritis (PsA)

Inclusion Criteria:

Has had Psoriatic Arthritis (PsA) for at least 6 months before the first administration of study drug and meet classification criteria for Psoriatic Arthritis (CASPAR) at Screening

Had active PsA as defined by:

At least 3 swollen joints and at least 3 tender joints at Screening and at baseline
C-reactive protein (CRP) greater than or equal to (>=) 0.3 milligram (mg)/deciliter (dL) at Screening from the central laboratory
Has at least 1 of the PsA subsets: distal interphalangeal joint involvement, polyarticular arthritis with absence of rheumatoid nodules, arthritis mutilans, asymmetric peripheral arthritis, or spondylitis with peripheral arthritis
Has plaque psoriasis with body surface area (BSA) involvement greater than or equal to (>=) 3% at Screening and baseline
Has active PsA despite current or previous non-biologic disease-modifying antirheumatic drugs (DMARD), oral corticosteroid, and/or nonsteroidal anti-inflammatory drug (NSAID) therapy
If using methotrexate (MTX), oral corticosteroids or NSAIDs, the dose must be stable

Exclusion Criteria:

Have other inflammatory diseases that might confound the evaluations of benefit of guselkumab therapy, including but not limited to rheumatoid arthritis (RA), ankylosing spondylitis (AS), systemic lupus erythematosus, or Lyme disease
Has previously received guselkumab or ustekinumab
Has received more than 1 type of biologic anti-tumor necrosis factor (TNF) agent previously
Have received infliximab (or its biosimilars) or golimumab intraveneous (IV) within 12 weeks before the first administration of study drug
Have received adalimumab (or its biosimilars), golimumab subcutaneous (SC), certolizumab pegol or etanercept (or its biosimilars) within 8 weeks before the first administration of study drug